Method for fabricating tubes



1 1966 JEAN-PIERRE CATTANEO METHOD FOR FABRICATING TUBES 2 Sheets-Sheet1 Filed Oct. 5, 1962 INVENTOR. JEAN-PIERRE CATTANEO ATTORNEY Sept. 6,1966 JEAN-PIERRE CATTANEO 3,

METHOD FOR FABRICATING TUBES Filed Oct. 5, 1962 2 Sheets-Sheet 2INVENTOR. JEAN-PIERRE CATTANEO ATTORNEY United States Patent METHOD FORFABRICATING TUBES Jean-Pierre Cattaneo, Geneva, Switzerland, assignor toRexall Drug and Chemical Company, Los Angeles, Calif., a corporation ofDelaware Filed Oct. 5, 1962, Ser. No. 229,285 Claims priority,application Switzerland, .Ian. 31, 1962, 1,246/ 62 3 Claims. (Cl.264-92) This invention relates to the manufacture. ofv plasticssqueezable tubes.

Known sqlueezable tubes made of plastics material suffer from thedrawback that they resume their original shape after squeezing out acertain quantity of their contents. Accordingly, it is generallyimpossible to determine at a glance whether such tubes are full,partially empty or completely empty.

An object of the present invention is to overcome this drawback.

According to one aspect of the invention there is produced a collapsibletube made of plastics material.

This invention also provides, according to another aspect, a method ofproducing a collapsible tube from a plastics squeezable tube having agenerally tubular body portion and a head portion at one end of saidbody portion, said method comprising the step of annulling the convexityof the outer surface of at least part of at least one axial half of saidbody portion whereby said part. comes to lie adjacent a correspondingpart of the other axial half of said body portion.

Moreover, the invention provides, according to a further aspect, anapparatus used for producing a collapsible tube from a plasticssqueezable tube having a generally tubular body portion and a headportion at one end of said body portion, said apparatus comprising heatand pressure deforming means for permanently deforming at least part ofat least one axial half of said body portion by heat and pressure tocause said part to [fall in and to come and lie adjacent a correspondingpart of the other axial half of said body portion.

For a better understanding of the invention and to show how the same maybe carried into effect, reference will now be made to the accompanyingdiagrammatic drawings in which:

FIGURE 1 is an elevational view of a first embodiment of an apparatusused according to the invention and illustrates one step in theoperation of the apparatus;

FIGURE 2 is a view similar to that shown in FIGURE 1 illustratinganother step in the operation of the apparatus;

FIGURE 3 is a section taken along line III-LII of FIGURE 2;

FIGURE 4 is a perspective view of the resultant tube;

FIGURE 5 is a perspective view showing the. shape of the tube aftersqueezing out part of the contents;

FIGURE 6 is an elevationalview of a second embodiment of an apparatusused according to the invention and.

illustrates one step in the operation of the apparatus;

FIGURE 7 is a cross-section taken along the line VII- VII of FIGURE 6;

FIGURE 8 is an elevational view similar to that of FIGURE 6 illustratinganother step in the operation of the apparatus; and

FIGURE 9 is a cross section taken along the line IX- IX of FIGURE 8.

The two illustrated 'forms of apparatus may each comprise the same basicstructure as that of known apparatus for manufacturing squeezable tubesmade of plastics material, erg. the basic structure of the apparatusdisclosed in Parmelees US. Patent No. 2,443,053 or of the apparatusdisclosed in Gvuignard U.S. patent application Serial No.

795,504.- As in the latter disclosure, the apparatus illustrated in\FIGURE 1 comprises a nozzle unit 1 carried by a frame (not shown). Inthis nozzle unit 1 is mounted an axially slidable core 2. This core 2 issurrounded by a tubular member 3 controlled by a servomotor adapted toimpart to the core 2 predetermined axial displacements within a sleeve 4of the nozzle unit. Between the sleeve 4 and the tubular member 3 isarranged an annular piston 5 for compressing heated plastics materialintroduced into the space between the sleeve 4 and the tubular member 3through a hopper '6. The tubular member 3 serves to ditribute heatedplastics material through the annular outlet 7, between the core 2 andan annular lip 8, of the nozzle unit 1. This nozzle unit 1 is adapted tocooperate with a die member 9 to form a collar 10 of the head portion ofa tube 11. In this connection, it should be noted that, at the initialstage of the manufacture of a tube, the die member 9' is in sealingengagement With the nozzle lip 8 and the core 2 occupies a retractedposition within the nozzle unit 1. A rforward movement of the piston 5then causes the injection of heated plastics material into the mouldingspace between the die member 9 and the end face 12 of the core 2 to formthe collar 10. The next step in the opera tion of the apparatus consistsin moving the die member 9 away (from the head 1 together with the core2 and in simultaneously extruding an additional quantity of heatedplastics material through the nozzle outlet 7 around the core 2 to forma generally tubular body portion or skirt 1-3 integral with the headportion of the tube 11. 1" hen, as shown in FIGURE 1, the core 2 ismostly withdrawn from the tube 11 which remainssecured to the die member9 by a threaded axially apertured neck 14 with which the head portion ofthe tube is provided. Now, the two forms of apparatus illustrated in thedrawings additionally comprise a device which is brought into actionbefore removing the tube 11 from the apparatus to deform part of thegenerally tubular skirt 1-3 of the tube and to bring this part intosubstantially parallel or contiguous relationship with the remainder ofthe skirt, the shape of the remainder of the skirt remaining unaltered.

In the first form of embodiment illustrated in the drawings, this devicecomprises a generally shell-like member 15 adapted to be moved (forexample by means of a servo-motor, not shown) into supporting engagementwith the part of the skirt 13 intended to preserve its shape, thisshell-like member having to this end a concave supporting surface whichis strongly cooled by, for example, circulating cooling water throughconduits 16 in the member 15.

Opposite the member 15 is provided a heat radiating member 17 which canalso be moved by a servo-motor (not shown). This heat radiating member17 may either be of the electric resistance type, or ofthe typeinvolving the circulation of a heated fluid, erg. steam. Members .15 and17 are intended to be moved adjacent the body portion of tube 11 and tocome into operation when the rear end portion 18 of the tube is still inengagement with the free end portion of core 2. The device then operatesas follows:

The heat radiated by the member 17 causes the material of skirt 13adjacent member 17 to soften and it then suffices to subject theinterior of the tube to a slight vacuum, for example with the aid of asuction channel 19 extending axially through the core 2, to cause theheated part of the skirt to fall in towards the opposite part, whoseinitial shape is preserved by the strongly cooled concave supportingsurface of the member 15. The tube then has the appearance shown inFIGURE 2, i.e. its skirt 13 has a par-t 20 of externally concave formwhich lies parallel to and adjacent the skirt part 21 maintained in itsexternally convex shape. The tube is then finished and can be removedfrom the apparatus Patented Sept. 6, 1966 3 by fully retracting the core2 within the nozzle unit 1 and by extracting the threaded neck 14 fromthe die 9.

The finished tube has, when empty, the shape shown in FIGURE 4. Its rearend 18 remains flared thus facilitating the filling operation of thetube. After closure of this end 18 by welding, the filled tube has theappearance of any other plastics tube made in known manner. However, asthe contents of the tube 11 are progressively squeezed out, its skirt 13tends to resume elastically the concave-convex shape imparted to itduring the manufacture. FIGURE 5 shows the shape of the tube 11 when itis partly empty. The tube will thus automatically give to the user aclear and unmistakable visual indication of the amount of substanceinside the tube.

The apparatus shown in FIGURES 6 to 9 comprises a modified form ofdevice for imparting to the skirt of the tube 11 a concave-convex shape.This modified device includes a shell-like member 22, similar to themember 15 in FIGURES 1 to 3, whose concave supporting surface is cooled,for example, by water circulation, and a heated member 23 having aconvex deforming surface substantially complementary to the concavesupporting surface of the member 22 (see FIGURES 7 and 9). Theservo-motor for actuating the member 23 is adapted to move the latterinto the shell-like member 22 and to press the skirt 13 of the tube 11between these members 22 and 23 thereby to impart to the skirt 13 itsconcave-convex shape (see FIGURES 8 and 9).

In this second constructional form, the rear end portion 18 of the tube11 is not flared as in the case of the tube shown in FIGURE 4.

Since the final shaping of the skirt 13 of the tube 11 between themembers 22 and 23 is effected by relative displacement of the members 23and 23 towards one another, there is no need for air to be sucked outfrom the tube 11 and the step of imparting to the skirt 13 itsconcave-convex cross-section may take place when the core 2 has alreadybeen fully retracted into the nozzle unit 1 of the apparatus.

Many constructional forms of the device for imparting to the skirt ofthe tube 11 the preferred concave-convex shape could be devised. Thus,the member 23 which is intended to impart to the part 20 of the skirt 13an externally concave shape could consist of a wheel or roller which canbe rolled along the tubular skirt 13 to cause its deformation. A devicecould also be devised which deforms part 20 of the tubular skirt 13after formation of the latter and which pinches the edges of thisdeformed part so that the latter keeps, when empty, the shape impartedto it.

In the embodiments described above, the device for imparting to theskirt 13 of the tube 11 a concave-convex shape, forms a part of the tubeforming apparatus. It should be understood, however, that this devicecould be independent of the tube forming apparatus, the tubes being thentreated in the device after removal from the tube forming apparatus.

Various thermoplastic molding materials may be used, as, for example,plasticized vinyl-chloride, and some of the other vinyl moldingcompounds, as well as cellulose plastics, such as cellulose acetate,cellulose nitrate, or ethyl cellulose, or such other plastics as maysuit themselves to the article which is to be formed.

I claim:

1. A method of producing a collapsible tube adapted for housing anddispensing a flowable commodity, said tube being fabricated from aflexible resinous thermoplastic material having a memory, said tubehaving a generally tubular body portion and an integral head portion atone end of said body portion, the head portion having a dispensingpassageway; said method comprising the step of deforming part of saidbody portion by application of heat and pressure differential to thepart to cause the part to become more readily deformable than theremainder of the tube and to annul the convexity thereof, said partbeing a major segment of only an axial half of said body portion andsaid part being deformed to lie adjacent to and spaced from acorresponding part of the other axial head of said body portion suchthat said part may be flexibly expanded to its position prior todeformation upon filling the tube with said commodity and the part willreturn to its deformed position due to said memory upon dispensing thecommodity from the tube.

2. Method according to claim 1 wherein the pressure differential is avacuum within the tube.

3. A method of making a flexible resinous thermoplastic collapsible tubehaving a generally tubular body portion and an integral head portion atone end of said body portion, said method comprising the steps ofinjecting heated plastic material through a nozzle into a space betweenthe die member and an end face of a core extending through said nozzleto form said head portion, simultaneously axially moving said end faceof the core and said die member away from the nozzle and extrudingheated plastics material around said core to form said body portion,fully withdrawing the core from said body portion, and pressing the bodyportion between a first shell-like member having a concave cooledsurface and a second cooperating shell-like member having a convexheated surface to deform a major segment of one axial half of said bodyportion to cause the inner surface of said part to lie substantiallyadjacent the inner surface of the corresponding part of the other axialhalf of said body portion having a concave configuration while retainingthe convex configuration for the outer surface of said other axial halfof the body portion, such that the concave body portion may be flexiblyextended to its position prior to deformation and it will return to itsdeformed position due to said memory.

References Cited by the Examiner UNITED STATES PATENTS 1,219,263 3/1917Davis 222--95 1,870,903 8/1932 Giesler. 2,326,041 8/ 1943 Lavallee264-92 2,418,155 4/1947 Bogoslowsky 264-296 2,422,325 6/1947 Wheelon264-320 XR 2,443,053 6/ 1948 Parmelee 264-296 2,748,455 6/ 1956 Draperet al. 2,803,695 8/ 1955 Woller 6t a1. 2,804,995 9/1957 Fee 222953,022,614 2/ 1962 Dreyfus et a1. 3,051,605 8/1962 Stannard 264- XR3,109,198 11/ 1963 Guignard.

ROBERT F. WHITE, Primary Examiner. ALEXANDER H. BRODMERKEL, Examiner. J.R. DUNCAN, M. R. DOWLING, Assistant Examiners.

1. A METHOD OF PRODUCING A COLLAPSIBLE TUBE, ADAPTED FOR HOUSING ANDDISEPNSING A FLOWABLE COMMODITY, SAID TUBE BEING FABRICATED FROM AFLEXIBLE RESINOUS THERMOPLASTIC MATERIAL HAVING A "MEMORY," SAID TUBEHAVING A GENERALLY TUBULAR BODY PORTION AND AN INTEGRAL HEAD PORTION ATONE END OF SAID BODY PORTION, THE HEAD PORTION HAVING A DISPENSINGPASSAGEWAY; SAID METHOD COMPRISING THE STEP OF DEFORMING PART OF SAIDBODY PORTION BY APPLICATION OF HEAT AND PRESSURE DIFFERENTIAL TO THEPART TO CAUSE THE PART TO BECOME MORE READILY DEFORMABLE THAN THEREMAINDER OF THE TUBE AND TO ANNUL THE CONVEXITY THEREOF, SAID PARTBEING A MAJOR SEGMENT OF ONLY AN AXIAL HALF OF SAID BODY PORTION ANDSAID PART BEIN DEFORMED TO LIE ADJACENT TO AND SPACED FROM ACORRESPONDING PART OF THE OTHER AXIAL HEAD OF SAID BODY PORTION SUCHTHAT SAID PART MAY BE FLEXIBLY EXPANDED TO ITS POSITION PRIOR TODEFORMATION UPON FILLING THE TUBE WITH SAID COMMODITY AND THE PART WILLRETURN TO ITS DEFORMED POSITION DUE TO SAID "MEMORY" UPON DISPERSING THECOMMODITY FROM THE TUBE.